Recovery and Atomicity To ensure atomicity despite failures,we first output information describing the modifications to stable storage without modifying the database itself. We study log-based recovery mechanisms in detail We first present key concepts And then present the actual recovery algorithm Less used alternative:shadow-copy and shadow-paging(brief details in book) db-pointer db-pointer old copy of shadow-copy old copy of database new copy of database (to be deleted) database (a)Before update (b)After update Database System Concepts-6th Edition 16.11 ©Silberschat乜，Korth and SudarshanDatabase System Concepts - 6 16.11 ©Silberschatz, Korth and Sudarshan th Edition Recovery and Atomicity To ensure atomicity despite failures, we first output information describing the modifications to stable storage without modifying the database itself. We study log-based recovery mechanisms in detail We first present key concepts And then present the actual recovery algorithm Less used alternative: shadow-copy and shadow-paging (brief details in book) shadow-copy